<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <script>
        // 编写函数，判断一个字符串是否是 “可回文字符串”
        function str(a){
            if(typeof a == "string"){
            var arr =a.split("");
           var newarr =arr.reverse();
            var newa = newarr.join("");
            if(newa == a){
                return true;
            }
            return false;
        }else{
            return -1;
        }
        }
        var a ="abcef";
        var res =str(a);
        console.log(res);
    </script>
</body>
</html>